I think you need to go to a more specialized forum, for example:
https://rog.asus.com/forum/forumdisplay.php?127-ROG-Discussion
Windows update problems DO NOT DAMAGE HARD DRIVES. It won’t do you any good to get a new hard drive. Note: the Bios information is stored on the motherboard, not the hard drive.
Your problem is that you need to change the BIOS information. You didn’t tell us the exact model number; here is a method for one model:
https://www.asus.com/support/FAQ/1030858/
I didn’t say that Win updates permanently damaged any drive, but they can corrupt HD data just like anything can. But installing an OS will probably wipe out any data in a existing drive, while using a new drive won’t, and I might be able to save the one file (not critical, but I can’t recreate it). 1TB drives aren’t that expensive, so I’ll use a new one.
I’ll have to check on the exact model, but if the BIOS points to a corrupted Windows boot manager, the problem isn’t in the BIOS. Thanks, I’ll take a look at your link.
If you’ve never installed any upgrades before this, is it possible that nothing’s “wrong”—it’s just doing a lot of updating all at once, which takes a looooong time?
Figure out some way to get it to run out the battery, so it’s really and for reals “off”. This may reset the device back into a normal boot mode afterwards.
That’s already been tried, accidentally, when I didn’t plug in the charging cable and it went off. Didn’t fix anything.
Not a bad idea, but it’s not updating, just recycling the boot. 8 hours on a 100Mb/sec internet connection with no progress shown? I don’t think so; Windows has regular progress reports during normal updates, and most take far less than an hour on this kind of connection. None of the standard reports say, “Undoing changes…”. My guess is it is stuck in some kind of recovery mode after a failed or aborted sequence, but it’s definitely in an endless loop.
Create a live Linux Boot (I like Knoppix) on a flash drive, remove the hard drive, which may be a major PITA and install the flash drive. The BIOS should cycle through whatever devices, including the flash drive trying to find something to boot. If Linux doesn’t boot, something in hardware is likely bad. Also, check if there’s a way to reset the CMOS which will take your BIOs back to factory fresh.
Edit: While you’re at it, unless your current drive is an SSD, now would be a good time to upgrade even if it’s a smaller drive. An SSD will much faster and better for a laptop than a mechanical drive. If you have a slim optical drive, you can get an adapter to replace it with your 1TB drive.
Found this, https://www.asus.com/support/FAQ/1013074, might be worth a shot.